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Introduction

Arboviruses, or viruses carried by arthropods such as mosquitoes or ticks (arthropod-borne viruses), are responsible for an estimated 700,000 deaths worldwide each year (Byaruhanga et al., 2023). With the changing global climate, the geographic distribution of these diseases, which include Zika, dengue, chikungunya, West Nile, and yellow fever, are steadily expanding. At the time of this workshop, half of the world’s population—about 4 billion people—are at risk of infection by dengue, a potentially fatal disease in its severe form (Brady et al., 2012; Madewell, 2020; WHO, 2023). To address this growing threat and the impact of global climate change, the Forum on Microbial Threats of the National Academies of Sciences, Engineering, and Medicine convened experts from medical entomology; local, state, and federal public health; ecology; arbovirology; immunology; disease modeling; and urban planning at a public workshop in Washington, DC, on December 12–13, 2023, to explore avenues of threat reduction from known and emerging arboviral diseases with a focus on building long-term public health resilience. This proceedings is developed from the presentations and discussions at the workshop, titled Mitigating Arboviral Threats and Strengthening Public Health Preparedness.¹

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¹ The planning committee’s role was limited to planning the workshop, and the workshop summary has been prepared by the workshop rapporteurs as a factual summary of what occurred at the workshop. Statements, recommendations, and opinions expressed are those of individual presenters and participants and are not necessarily endorsed or verified by the National Academies of Sciences, Engineering, and Medicine, and they should not be construed as reflecting any group consensus.

As workshop co-chair Thomas W. Scott of the University of California, Davis, presented in his opening remarks, arboviruses are a particularly difficult public health issue to address because of their complex transmission cycles. The presence of a vector host, such as a mosquito, in disease transmission complicates infection prevention measures because the vector organism has its independent ecology, population structure, genetics, and unique biological interactions with the virus. In some cases, there can be multiple vectors that are capable of infecting humans with the virus. Additional layers of complexity are introduced when non-human animals are part of the pathogen life cycle.² Either domesticated or wild animals can serve as reservoirs for these viruses, and as sources of unpredictable disease spillovers into human populations.

Despite these complexities and the challenges they present in identifying and implementing effective control strategies for arboviral diseases, Scott said, the workshop planning committee saw opportunities in achieving major public health advances to alleviate the vast toll of these diseases. Attributing this hope to tremendous advances in the field he observed in the past decade, Scott explained, “I’ve been working on arboviruses for about 47 years, and in the last 10 years I’ve seen the most innovation in the field of any time in my career.”

To further explore those advancements and remaining challenges, the Forum on Microbial Threats held the public workshop, Mitigating Arboviral Threats and Strengthening Public Health Preparedness,³ with the primary goal of highlighting promising scientific breakthroughs that can be translated into improved public health actions. The forum has held two prior workshops related to arboviruses. The first, held in 2007, sought to clarify the environments, human health, and ecological connections in the emergence and spread of vector-borne diseases (IOM, 2008). The second, held in 2014, examined the global health impacts of vector-borne diseases (NASEM, 2016). Scott pointed out that a central charge for this planning committee was to consider “how can we do things differently, in a sustainable way, to prevent arboviral diseases” in the face of the growing geographical distribution of arboviruses and the toll of these diseases. The aim of the workshop was to explore the role of arbovirus mitigation

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² One example is the transmission of Lyme disease, where the arthropod vector (black-legged tick) carrying the disease-causing bacteria can feed and proliferate on a wide range of non-human vertebrate hosts including birds, lizards, and other mammals that contribute to a persistent pathogen reservoir. See https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5879012/ (accessed June 30, 2024).

³ Video recordings of this workshop and all slide decks used by speakers are available on the Forum on Microbial Threats’ webpage. https://www.nationalacademies.org/event/40925_12-2023_mitigating-arboviral-threats-and-strengthening-public-health-preparedness-a-workshop (accessed July 1, 2024).

within the context of public health preparedness and capacity building. Discussion focused on potential actions that can be taken to understand and mitigate arboviral disease threats and highlight priority areas for research and investment.⁴

STRUCTURE OF THE PROCEEDINGS

The workshop’s first day centered on the current landscape of arboviral threats and factors in assessing their risks to human health. Chapter 1 summarizes introductory remarks that explain the context and rationale for convening this workshop. Chapter 2 provides an overview of global arbovirus research priorities as well as current and emerging arboviral disease threats, noting in particular the knowledge gaps and key challenges. Chapter 3 covers topics of detecting and assessing arboviral risks to guide and evaluate various intervention strategies. Chapter 4 is devoted to various responses to arboviral threats, including surveillance, vector control, vaccines, and predictive tools. Chapter 5 delves into lessons learned from previous outbreaks of arboviruses and from the COVID-19 pandemic, and how these lessons might guide future responses.

The second day of the workshop centered on innovations for future arboviral disease mitigation. Chapter 6 examines the spillover and spread of arboviruses and how this knowledge may inform interventions. Chapter 7 focuses on urban development and how constructing and managing urban environments could have a sustainable impact on arboviral infections. Chapter 8 captures reflections from workshop speakers who highlighted ideas from the workshop that they found to be the most consequential in strengthening preparedness for future arboviral disease outbreaks. A short synthesis of the workshop’s key themes from Scott at the close of the workshop is presented in Chapter 9.

REFERENCES

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⁴ The full Statement of Task is provided in Appendix A. The workshop agenda is provided in Appendix B.